Extension-ladder



' (No Model.)

' J. E. SMITH.

EXTENSION LADDER.

No.369,084. E E Patented Augs.

, UNITED STATES PATENT Denice.

JOHN E. SMITH, OF COLUMBUS, OHIO.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent No. 369,084, dated August30, 1887.

Application filed June 13, 1887. Serial No. 241,127. (No model.)

To all whom it may concern.-

Be it known that 1, JOHN E. SMITH, of Colurnbus, Franklin county, Stateof Ohio, have invented a new and useful Improved Extension- Ladder, ofwhich the following is a true and exact description, due reference beinghad to theaccompanying drawings, which form a part of thisspecification.

The object of my invention is to provide an extensionladder of simpleconstruction which can be readily and safely adjusted to any desiredlength and as readily contracted; and it consists of two or moreladder-sections coupled and united with each other to form anextension-ladder by means of the devices hereinafter fully described,and illustrated in the drawings, in which- Figure 1 is a front view ofmy improved extension ladder, consisting of two sections, which is mypreferred arrangement. Fig. 2 is a side view of myladder; Fig. 3, a sideview of the inside of my ladder, showing the devices secured at or nearthe lower end of the upper ladder-section; Fig. 4, a perspective View ofthe clamp or guide which I secure at the top of the lowerladder-section, with its attachments; and Fig. 5, a perspective view ofthe clamp or guide which I secure at the lower end of the upperladder-section, with its attachments.

A is the lower and B the upper ladder-sections, which may be of anyordinary construction, and are preferably made so that the upper sectionshall fit in between the side pieces of the lower section and upon therounds of the ladders.

G O are clamps or guides secured near the top of the lower section, A.They are preferably made, as shown in Fig. 4, with a recess, D, adaptedto pass around the three outer sides of the side piece, to which it issecured by a bolt or any ordinary fastening, and are provided with aprojecting tongue or lug, E, extending upward and then inward, so as topass over the side piece of the upper section, B. To the side of thisguide-clamp O, I prefer to secure my pulley-bracket F, in which are thebearings of the pulley 0, though, as will be seen, this bracket F may besecured to the ladder-section A independently of the guide 0.

D D are guideclamps which are secured near the bottom of the uppersection, B, of my ladder. They, as isshown in Fig. 5, are provided withrecesses H, which embrace the upper edges of the side pieces to which itis secured, and have a lug or tongue, G, which passes downward andinward, so as to embrace the side pieces of the lower section, A, andclamp it to the ladder. To these gnideclamps D, I preferto securesprings J, a projection, I, being preferably formed with the clamp D forthat purpose; but, as in the case of the pulleybrackets F, it is obviousthat the spring may be secured to the ladder independent of the clamp.

K is a catch-lever of the bellcrank order. It is pivoted on the upperladder-section, B, and has at the end of one arm a crotch adapted torest over and hold, to the laddenrungs at. Its other or outer arm is theone by which it is actuated, as will be hereinafter described. Thespring J is arranged so that it will constantly press against the leverK in such a way as to press the crotched arm in toward the rungs of thelower ladder-section, a stop, is,

. being provided so as to make the normal position of the crotch 7ccorrespond with that of the rungs a on this section. cured at one end tothe actuating-arms of the levers K, passing thence over the pulleys cand downward, their other ends being conveniently fastened to the sidesof the lower laddersection, A, as shown.

The sections A and B of my ladder being put together and the clamps Oand D secured to them in the manner shown and described, the twosections are free to slide longitudinally on each other, but aresecurely clamped together as against any other movement. When the ladderis erected, as is shown inFigs. 1 and 2, the clutch-lever K holds theupper section, B, in position by resting on one of the rungs a of thesection A. If, now, it is desired to lengthen the ladder, the usergrasps the ropes L, and by pulling on them draws the upper section, B,to any desired height, the levers K being drawn outward away from therungs of the lower ladder by the pull, which overcomes the pressure ofthe springs J. When the ladder is extended sufficiently, the pull uponthe ropes is relaxed, so as to let the springs J force the levers K backto their nor- L L are ropes se-.

ICO'

mal position, where they will grip and rest upon the rung immediatelybelow them. A stop is of course provided to prevent the levers K frombeing pulled too far from their normal position, the lug I serving thepurpose in the construction illustrated. Vhen it is desired to retractthe upper section, the ropes L are drawn upon sufficiently to releasethe lovers K from the ladder-rungs, and the upper ladder-section canthen easily be drawn down or allowed to fall of its own weight,sufficient pressure being maintained on the ropes to prevent the loversfrom engaging during its descent.

While I prefer to use the spring J to keep the lever K in its normalposition, it may be dispensed with and the lever-arms so weighted as toperform the same function, I would also state that as these ladders aregenerally light it is not always necessary to employ a rotating pulleysuch as c, any smooth surface over which the ropes L will run freelybeing its manifest equivalent in this connection.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In an extension-ladder, the combination of the sections A and B,fitting upon each other, with the guide-clamps G D, pulley c, secured 30at the top of the lower ladder-section, clutchlevers K, secured near thebottom of the upper ladder-section, and ropes L, attached to said leversand passing through the pulleys c, all substantially as and for thepurpose specified.

2. In an extension-ladder, the combination of the sections A and B,fitting upon each other, with the guide-clamps G D, pulley a, secured atthe top of the lower ladder-section, clutchlevers K, secured near thebottom of the upper ladder-section, springs J, arranged to press againstthe levers and keep them in position to engage the ladder-rungs, andropes L, attached to said levers and passing through the pulleys c, allsubstantially as and for the purpose specified.

3. In an extension-ladder, the combination of the ladder-sections A B,fitting upon each other, with clamp-guides O and pulley-brackets F,secured to the upper ends of the sections A, clamp-guides D and leversK, secured to the lower end of the section B, springs J, attached tothe'elamps D and acting on levers K, as specified, and ropes secured tolevers K and passing over pulleys c, all substantially as and for thepurpose specified.

JNO. E. SMITH.

\Vitnesscs:

Enwn. B. WALL, \V. B. VAGGONER.

